1. Technical Field
Novel photoresist polymers and photoresist compositions containing the same are disclosed. In particular, photoresist polymers suitable for a photolithography process using DUV (deep ultraviolet) light source, such as VUV (157 nm) in fabricating minute circuit for highly integrated semiconductor devices, photoresist compositions containing the same, and preparing process therefor are also disclosed.
2. Description of the Related Art
A photoresist for an ArF and VUV (vacuum ultraviolet) should have low absorbency at 193 nm and 157 nm wavelengths, excellent etching resistance and adhesiveness on a substrate, and should be easily developable in a commercially available developing solution, such as aqueous tetramethylammonium hydroxide (TMAH) solution of 2.38 wt % or 2.6 wt %.
Recently, much research has been conducted on resins having a high transparency at 248 nm and 193 nm wavelengths and dry etching resistance similar to novolac resin. However, most of the resists are not suitable for VUV due to their high absorbency at 157 nm wavelength.
Photoresists containing fluorine have also been studied to solve the above problem. However, most polyethylene, polystyrene or polyacrylate polymers containing fluorine have weak etching resistance, low solubility in aqueous TMAH solutions and poor adhesiveness to the silicon wafer. In addition, these photoresists are difficult to mass-produce and are expensive.
Novel photoresist polymers containing fluorine-substituted maleimide are disclosed.
Photoresist compositions containing the photoresist polymers described above and processes for forming photoresist patterns are also disclosed.
Semiconductor elements produced using the photoresist compositions described above are also disclosed.